TITLE:
2-D Resistivity Study: The Horizontal Resolution Improvement by Introducing the Enhancing Horizontal Resolution (EHR) Technique
AUTHORS:
M. M. Nordiana, Rosli Saad, M. N. M. Nawawi, Nisa’ Ali, I. N. Azwin, A. H. A. Teh Saufia
KEYWORDS:
2-D Resistivity; EHR Technique; Mineral Exploration; Geology; Engineering and Environment
JOURNAL NAME:
Open Journal of Geology,
Vol.3 No.2B,
October
22,
2013
ABSTRACT: 2-D resistivity method is an indirect method to the shallow subsurface
survey for maintaining the geo-environment. It is used
to measure the apparent resistivity of subsurface. EHR technique was developed
in order to get detail and deeper penetration for shallow subsurface study. In
this study, 2-D resistivity with Enhancing Horizontal Resolution (EHR)
technique is adopted to map and characterize the shallow subsurface (mineral
exploration, geology, engineering and environment) using Pole-dipole array. The
locations are Pagoh, Johor; Nusajaya, Johor and Puchong, Selangor (Malaysia).
The study associated with mineral exploration is Pagoh, Johor while for
Nusajaya, Johor is associated with geology and Puchong, Selangor is associated
with engineering and environment. The 2-D resistivity and Induced polarization
(IP) were employed at Pagoh, Johor to study and detect the subsurface variation
of resistivity and chargeability of iron ore in the area. Result of the 2-D
resistivity as well as the Induced Polarization (IP) shows that
the area is underlain by a thick alluvium with resistivity value of 10 - 800
ohm-m iron which has chargeability rate of 0.1 - 3 msec.
A sedimentary case study was executed at Nusajaya, Johor shows sandstone
contains iron mineral (30 - 250 ohm-m) and weathered sandstone (500 -1000
ohm-m). Interpretation of 2-D resistivity data at Puchong, Selangor showed a
low resistivity value (and this could be an influence factor the increasing water level because
sandy silt is highly permeable in nature. The borehole,
support the results of 2-D resistivity method relating a saturated zone in the
survey area. There is a good correlation between the 2-D resistivity investigations
and the results of borehole records. The stratigraphy and structure of the
three case studies (mineral exploration, geology, engineering and environment)
can be mapped effectively using 2-D resistivity with EHR technique.